Fixes length calculation for str_slice edge cases

1 files changed, 2 insertions, 2 deletions

diff --git a/scss/extension/core.py b/scss/extension/core.py
index c1bdd53..7967429 100644
--- a/scss/extension/core.py
+++ b/scss/extension/core.py
@@ -578,11 +578,11 @@ def str_slice(string, start_at, end_at=None):
     expect_type(start_at, Number, unit=None)
 
     if int(start_at) == 0:
-        py_start_at = 1
+        py_start_at = 0
     else:
         py_start_at = start_at.to_python_index(len(string.value))
 
-    if end_at is None or int(end_at) > len(string):
+    if end_at is None or int(end_at) > len(string.value):
         py_end_at = None
     else:
         expect_type(end_at, Number, unit=None)